JP2550851B2 - Mail protocol conversion control system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mail protocol conversion system in the case of sending and receiving a mail in electronic mail, when the mail systems to be sent and received have different protocols.

[0002]

2. Description of the Related Art The so-called network architecture, which is a system that defines the protocols and interfaces of computer networks, differs from computer manufacturer to computer company. When sending and receiving electronic mail between these different network systems, the mail protocol It is necessary to carry out the conversion.

JP-A-02-1659 and JP-A-03-12
3240 describes a process in which, when a plurality of different electronic mail systems exist in one computer system, the mail format conversion means converts the format of the mail sent by the sender mail system and transfers it to the receiver mail system. ing.

Japanese Patent Laid-Open No. 03-76452 describes a so-called gateway process in the case where a computer system having a plurality of different protocols exists on one network system.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
When there are a plurality of different electronic mail systems in one computer system, the mail format conversion means is activated in response to a request from the receiving mail system, and the sending mail system uses the mail in its own mail system. Since the format of the mail in the box is converted and passed to the receiving mail system, the processing of the mail format conversion means is not executed unless the receiving mail system issues a format conversion request. If there is no format conversion request for, there is a problem that mails will be stored in the mailbox of the sender mail system forever. Also, the mail format conversion means is a series of processes depending on the activation from the receiving mail system, and since the mail format conversion process and the mail reception process are not performed asynchronously, especially when the amount of mail data is large. Has a problem that the processing efficiency may be significantly deteriorated. Further, although it is not mentioned when an error occurs in the series of processes, it seems that the receiving mail system needs to restart the process from the start of the mail format conversion means, and there is a problem that the processing efficiency is poor. .

Japanese Patent Laid-Open No. 03-76452 describes a so-called gateway process in the case where a computer system having a plurality of different protocols exists on one network system.
A series of processes from sending an e-mail to going through protocol conversion to receiving is performed, and the next e-mail is sent after the series of processes is completed, so the processing efficiency is remarkably high especially when the amount of mail data is large. There is a problem that may worsen. Further, although it is not mentioned when an error occurs in a series of processes, it seems that it is necessary to restart the process from the transmission of the mail, and there is a problem that the processing efficiency is low.

Japanese Laid-Open Patent Publication No. 03-123240 discloses that when a plurality of different electronic mail systems exist in one computer system, the mail format conversion means is activated by the mail system on the sending side to convert the format of the mail and the mail system on the receiving side. It is configured to deliver to one email. From the sending of one email, through protocol conversion, to receiving is a series of processing, and the next email is sent after this series of processing is completed. When the amount is large, there is a problem that the processing efficiency may be significantly deteriorated. Further, although it is not mentioned when an error occurs in a series of processes, it seems that it is necessary to restart the process from the transmission of the mail, and there is a problem that the processing efficiency is low.

[0008]

A mail protocol conversion control system according to the first invention is a mail protocol conversion control for converting a mail protocol necessary for transmitting and receiving a mail between electronic mail systems having different protocols. In the system, a first mail transmission means for setting a reception mailbox for another mail system with a different protocol in the own mail system and transmitting a mail from the transmission mailbox to the reception mailbox for another mail system A mail protocol conversion device that is set according to different protocols, takes out mail from its own mail system, converts the mail protocol by a preset conversion method, and sends it to another mail system. Register the status that holds the status And Lumpur status file means,
An outgoing mail waiting means for taking out the mail from the other mail system mailbox in the own mail system and registering the mail in the mail status file means,
A mail protocol conversion means for extracting a mail from the mail status file means, converting a mail protocol by a preset conversion method, and returning the mail protocol to the mail status file means, and a protocol-converted mail of the mail status file means to another mail system. It is configured to include a second mail sending means for sending to the mail and a sending history updating means for monitoring the status of the mail in the mail status file means and returning the mail sending history to the own mail system.

The mail protocol conversion control system of the second invention is a mail protocol conversion control system for converting a mail protocol necessary for transmitting and receiving a mail between electronic mail systems having different protocols. The first mail sending means for sending mail from the sending mailbox to the post mail status file means in the post mail protocol conversion device and the mail from the own mail system to convert the mail protocol to another mail A mail protocol conversion device for sending to a system, which receives a mail from its own mail system, registers mail and a status for holding the processing status of the mail, and a mail status file means for extracting the mail from the mail status file means. Referring to the protocol conversion table, the mail protocol is converted and returned to the mail status file means, and the second mail transmission for sending the protocol-converted mail of the mail status file means to another mail system And a sending history updating means for monitoring the status of the mail in the mail status file means and returning the mail sending history to the own mail system.

A mail protocol conversion control system of a third invention is a mail protocol conversion control system for converting a mail protocol necessary for transmitting and receiving a mail between electronic mail systems having different protocols. The mail status file means for registering the mail status holding the processing status, the mail editor means for editing the mail and putting the mail in the outgoing mailbox or the mail status file means, and the mail status from the mail status file means. A mail protocol conversion means for asynchronously extracting a mail indicating protocol unconverted, converting the mail protocol by referring to the mail protocol conversion table, and returning the mail status file means to the mail status file And a mail sending means for asynchronously taking out the mail whose mail status indicates that the protocol has been converted from the mail means and sending it to another mail system.

[0011]

The present invention will be described below with reference to the drawings.

Referring to FIG. 1, a mail protocol conversion control system according to a first embodiment of the present invention includes a mail system A1 and a mail system A1 which are mail senders.
A sending mailbox for storing outgoing mails in the mail 2, a first mail sending means 3 for sending mails, and another mail system for storing mails to the mail system B in the mail system A1 and having different protocols Receiving mailbox 4, and mail protocol converter 5 for converting the mail protocol sent by mail system A1 addressed to mail system B11 and for receiving another mail system in mail system A1 in mail protocol converter 5 The mail stored in the mailbox 4 is taken out, and the outgoing mail waiting means 6 is stored in the mail status file means 7 to be described later. The mail status file means 7 holds the mail and the processing status of the mail. A mail that has not been converted into a Tokoru is taken out, the mail protocol is converted by a preset conversion method, and the mail is returned to the mail status file means 7. Second to send mail to mail system B11
Mail sending means 9, a mail history in the mail status file means 7, and a sending history updating means 10 for notifying the mail sending history to the mail system A1, and a mail system B1 which is a mail receiving side.
1. The mail system B11 includes a reception mailbox 12 in the mail system B11 for storing reception mail.

Next, regarding the operation of the first embodiment of the present invention, referring to FIG. 1, FIG. 2 and FIG. 3, an example of sending a mail from the mail system A1 to a mail system B11 having a different protocol will be described. As described below.

Mails to other mail systems are stored in the outgoing mail box 2 in the mail system A1. First, the first mail sending means 3 checks whether or not there is a mail in the outgoing mail box 2. Is determined (Step 2
1) If there is a mail, one mail is taken out from the sending mailbox (step 22). Next, the first mail transmitting means 3 first determines whether or not the extracted mail is a mail to a mail system of a different protocol (step 23), and if the mail is a mail to a mail system of the same protocol, , And sends a mail to the mail system (step 24: This process is a process of a known electronic mail system, and therefore detailed description thereof is omitted). If the mail is to a mail system of a different protocol, the mail is not sent to the mail system, but is sent to the receiving mail box 4 for another mail system preset in the mail system A1. Make a call (step 2)
5).

The format of the receiving mailbox for the other mail system is the same as the format of the receiving mailbox for the mail system A1.

The sending mailbox 2 and the receiving mailbox 4 for another mail system in the mail system A1 hold a mail processing flag of a normal mail system, and these flags are respectively set in the above-mentioned steps 25 and 25. In response to the processing of step 33 described later, the state of "calling" is set. This flag becomes "transmitted" in the processing of step 3E and step 28 described later, and the transmission processing of one mail is completed.

In the present invention, the mail protocol converter is set corresponding to each different protocol. The number is several to ten or more, and it is not unrealistic to set.

In this embodiment, the outgoing mail waiting means 6 in the mail protocol converter 5 for the mail system B is asynchronous with the processing of the first mail sending means 3 in the mail system A1. It is judged whether or not the mail for the mail system B is sent in the receiving mail box 4 for another mail system in the above (step 31), and if the mail is sent,
Further, it is judged whether or not the mail is already in the mail status file means 7 by using the mail ID (step 32). If there is a mail not in the mail status file means 7, the other mail is selected. It is taken out from the mail system reception mailbox 4 and stored in the mail status file means 7 (step 33). In the mail status file means 7, the mail is registered together with the status holding the processing status of the mail. The outgoing-waiting mail extracting means 6 has a status 3
When storing the mail in the mail status file means 7 in 3, the status is set to "not converted" (step 34).

The mail protocol conversion means 8 in the mail protocol conversion device 5 uses the outgoing mail waiting means 6
Mail status file means 7 asynchronously with the processing of
It is determined whether or not there is a mail whose status is "unconverted" (step 35), and when there is a mail whose status is "not converted", one mail is taken out from the mail status file means 7 (step 36) Next, the mail is protocol-converted by the protocol conversion method preset for the mail system B (step 3).
7) The converted mail is returned (replaced) to the mail status file means 7, and at that time, the status of the mail is set to "converted" (step 38).

The second mail transmission means 9 in the mail protocol conversion device 5 determines whether or not there is a mail whose status is "converted" in the mail status file means 7 asynchronously with the processing of the mail protocol conversion means 8. Is judged (step 39), and if there is a mail whose status is "converted", one of the mails is taken out from the mail status file means 7 (step 3A), and the mail system B is sent.
Send a mail to the receiving mailbox 12 in 11,
At that time, the status of the mail is set to "sent" (step 3B).

In step 3A, the mail is taken out from the mail status file means 7, but at that time, a copy of the mail is placed. This is step 3B
This is because if the substance of the mail is lost in the transmission history updating means 10 described later, the status of the mail cannot be processed.

The sending history updating means 10 in the mail protocol conversion device 5 is asynchronous with the processing of the second mail sending means 9 and whether or not there is a mail whose status is "sent" in the mail status file means 7. Is judged (step 3C), and if there is a mail whose status is “sent”, the mail and the status are deleted from the mail status file means 7 (step 3D), and the mail corresponding to the mail ID of the mail, "Sent" is notified to the mail processing flag of the receiving mail box 4 for another mail system in the system A1 (step 3E).

The first mail sending means 3 in the mail system A1 determines whether or not there is a mail whose mail processing flag is "sent" among the mails in the receiving mail box 4 for another mail system in the mail system A1. Is judged (step 26), and if there is a mail whose mail processing flag is “sent”, that mail is deleted from the receiving mailbox 4 for another mail system (step 27), and the mail 1D of the mail is added. Correspond. Notify that the mail has been sent to the mail processing flag in the outgoing mailbox 2 (step 2)
8).

The error processing in the present invention is set in advance by the first mail transmitting means 3, the transmission waiting mail extracting means 6, the mail protocol converting means 8, the second mail transmitting means 9, and the transmission history updating means 10, respectively. When the retry is unsuccessful as a result of the retry, the first mail transmitting means 3 directly to the mail system A1 and the mail status file means from the other means to the mail system A1. 7. "Unsuccessful" is returned as information of the mail processing flag of the normal mail system via the transmission history updating means 10.

Through the above processing, the transmission processing of one mail is completed.

In the first embodiment of the present invention, the mail system A1 and the mail protocol conversion device 5 are separate devices so that each process in the mail protocol conversion device can be carried out. There is an effect that it does not become a load on the device that operates.

Referring to FIG. 4, the mail protocol conversion control system according to the second embodiment of the present invention includes a mail system A1 and a mail system A1 which are mail senders.
A mail box for storing a mail for sending, a first mail sending means 3 for sending a mail, and a mail protocol conversion for converting a mail protocol addressed to a mail system B10 having a different protocol sent by the mail system A1 Device 4, mail protocol conversion device 4 Mail status file 5 for holding mail and mail processing status 5, mail for which mail protocol conversion is not performed is taken out from the mail status file means 5, and mail protocol is converted according to mail protocol conversion table 7 described later. Convert the mail status file means 5
To return to the mail protocol conversion means 6, the mail protocol conversion table 7 defining the conversion method of the mail protocol,
The mail that has undergone the mail protocol conversion is taken out from the mail status file means 5, and the mail system B10
A second mail sending means 8 for sending a mail to the recipient, a sending history updating means 9 for monitoring the status of the mail in the mail status file means 5 and notifying the mail system A1 of the mail sending history, and further receiving the mail. The mail system B10 which is the side, and the mail system B10 which stores the mail for reception in the mail system B10
It is composed of a receiving mailbox 11 inside.

Next, regarding the operation of the second embodiment of the present invention, referring to FIG. 4, FIG. 5 and FIG. 6, an example of a case where a mail is transmitted from the mail system A1 to a mail system B10 having a different protocol is taken as an example. As described below.

Mails to other mail systems are stored in the outgoing mail box 2 in the mail system A1. First, the first mail sending means 3 checks whether or not there is a mail in the outgoing mail box 2. Is determined (step 5
1) If there is a mail, one mail is taken out from the outgoing mail box 2 (step 52). Then the first
The mail transmitting means 3 first determines whether the retrieved mail is a mail to a mail system of a different protocol (step 53), and if the mail is a mail to a mail system of the same protocol, the mail system. A mail is sent to (step 54: this processing is processing of a known electronic mail system, so detailed description will be omitted). If the mail is for a mail system of a different protocol, the mail is not sent to the mail system, for example, not to the mail system B10 in this embodiment, but to the mail protocol converter. A mail is sent to the mail status file means 5 in 4 (step 55).

The sending mailbox 2 in the mail system A1 holds a mail processing flag of a normal mail system, and this flag corresponds to the processing of the above step 55 and is in a "sending" state. To be This flag becomes "sent" in the process of step 6A described later, and the sending process of one mail is completed. Further, in the mail status file means 5 in the mail protocol converter 4, a status for holding the processing status of the mail is added to the mail. In step 55,
When the first mail sending means 3 in the mail system A1 sends a mail to the mail status file means 5, this status is "unconverted" by default.

The mail protocol converter 6 in the mail protocol converter 4 determines whether or not there is a mail whose status is "unconverted" in the mail status file 5 asynchronously with the processing of the first mail transmitter 3. (Step 61), and if there is a mail whose status is "unconverted", one of the mails is taken out from the mail status file means 5 (step 62), and then that mail is converted to a preset mail protocol. Protocol conversion is performed according to Table 7 (step 63), the converted mail is returned (replaced) to the mail status file means 5, and at that time, the status of the mail is set to "converted" (step 64).

The conversion information in this protocol conversion table 7 is
Although the number of different protocols is set, the number is from a few to ten or more, and it is not unrealistic to set.

The second mail sending means 8 in the mail protocol converter 4 determines whether or not there is a mail whose status is "converted" in the mail status file means 5 asynchronously with the processing of the mail protocol converter 6. Is judged (step 65), and if there is a mail whose status is "converted", one of the mails is taken out from the mail status file means 5 (step 66), and is stored in the receiving mailbox 11 in the mail system B10. A mail is sent, and at that time, the status of the mail is set to "sent" (step 67).

In step 66, the mail is taken out from the mail status file means 5, and at that time, a copy of the mail is placed. This is step 67
This is because the status of the mail cannot be processed if the substance of the mail is lost in the transmission history updating means 9 described later.

The sending history updating means 9 in the mail protocol converter 4 determines whether or not there is a mail whose status is "sent" in the mail status file means 5 asynchronously with the processing of the second mail sending means 8. Is determined (step 6
8) If there is a mail whose status is "sent", delete the mail and status from the mail status file means 5 (step 69), and delete the mail in the mail system A1 corresponding to the mail ID of the mail. "Sent" is notified to the mail processing flag of the sending mailbox 2 via the mail sending means 3 of No. 1 (step 6).
A).

In the error processing according to the present invention, the first mail transmission means 3, the mail protocol conversion means 6, the second mail transmission means 8 and the transmission history update means 9 each retry the preset number of times. However, if the result of the retry is unsuccessful, the first mail transmission means 3 directly to the mail system A1 and the mail status file means 5 and the transmission history update means 9 from other means. “Unsuccessful” is returned as information of the mail processing flag of the normal mail system via.

Through the above processing, the transmission processing of one mail is completed.

In the second embodiment of the present invention, the mail system A1 and the mail protocol converter 4 are separate devices, so that each process in the mail protocol converter can be executed. There is an effect that it does not become a load on the device that operates.

Further, by arranging the mail protocol conversion table 7 in the mail protocol conversion device 4, it is possible to set a receiving mailbox for each different protocol in the mail system A1 or to set the mail protocol conversion device 4 itself to a different protocol. It is not necessary to set each time.

Referring to FIG. 7, in the mail protocol conversion control system according to the third embodiment of the present invention, the mail system A1, which is the sender of the mail, edits the mail to make a mail box 7 for sending or the mail status described later. A mail editor for placing mail in the file means 3, a mail status file means for holding mail and the processing status of the mail 3, mail for which mail protocol conversion has not yet been performed is taken out from the mail status file means 3, and mail according to the mail protocol conversion table 5 below. Convert protocol,
The mail protocol conversion means 4 for returning to the mail status file means 3, the mail protocol conversion table 5 which defines the conversion method of the mail protocol 5, the mail which has undergone the mail protocol conversion is taken out from the mail status file means 3, and a mail system B8 described later. A mail sending means 6 for sending a mail to a mail, an outgoing mail box 7 for storing outgoing mail to a mail system having the same protocol as the mail system A1 in the mail system A1, and a mail system B8 which is a recipient of the mail. ,
The mail system B8 is composed of a reception mailbox 9 for storing reception mail.

Next, with reference to FIGS. 7 and 8, the operation of the third embodiment of the present invention will be described by taking the case of sending a mail from the mail system A1 to a mail system B8 having a different protocol as an example. .

In the mail system A1, the mail editor 2 edits a mail and puts a mailbox in
It is determined whether or not the mail is to a mail system of a different protocol (step 81), and if the mail is a mail to a mail system of the same protocol, the mail is placed in the outgoing mailbox 7 (step 82). : Since this process is a process of a known electronic mail system, detailed description will be omitted). If the mail is for a mail system of a different protocol, the mail is not placed in the sending mailbox 7 but is placed in the mail status file means 3 (step 83).

The format of the mail status file means 3 is the same as that of the outgoing mail box 7, and in the mail status file means 3, a status for holding the processing status of the mail is added to the mail. This status has the same format as the mail processing flag of the outgoing mailbox 7 and is used for the same purpose. Step 83
In the above, when a mail is placed from the mail editor 2 to the mail status file means 3, this status is "not converted" by default.

The mail protocol conversion means 4 determines whether or not there is a mail whose status is "unconverted" in the mail status file means 3 asynchronously with the processing of placing the mail from the mail editor 2 to the mail status file means 3. Judged (step 84) and status is "not converted"
, There is one mail from the mail status file means 3 (step 85),
Next, the mail is protocol-converted according to the preset protocol conversion table 5 (step 86), and the converted mail is returned (replaced) to the mail status file means 3,
At that time, the status of the mail is set to "converted" (step 87).

The conversion information in this protocol conversion table 5 is
Although the number of different protocols is set, the number is from a few to ten or more, and it is not unrealistic to set.

The mail sending means 6 determines whether or not there is a mail whose status is "converted" in the mail status file means 3 asynchronously with the processing of the mail protocol converting means 4 (step 88), and the status is "Converted"
If there is an e-mail, the e-mail is taken out from the mail status file means 3 (step 89),
A mail is sent to the receiving mail box 9 in the mail system B8, and at that time, the status of the mail is set to "sent" (step 8A).

The mail transmitting means 6 performs processing on the transmission mail box 7 in addition to the processing from step 88 to step 8A, but as described above, this processing is processing of the known electronic mail system. , Detailed description is omitted.

In the error processing according to the present invention, the mail editor 2, the mail protocol conversion means 4, and the mail transmission means 6 each perform a preset number of retries, but when the result of the retries is unsuccessful. Directly from the mail editor 2 to the mail system A1,
From other means, "unsuccessful" is returned as the information of the mail processing flag.

Through the above processing, the transmission processing of one mail is completed.

In the third embodiment of the present invention, since the mail protocol conversion is carried out within the mail system A1, it is not necessary to set another device for the protocol conversion.

[0051]

As described above, in the present invention, in the mail protocol conversion, the mail status file means is used, the processing such as the mail transmission and the protocol conversion is made independent, and the respective processings can be asynchronously processed in parallel. As a result, it is possible to improve the processing efficiency of mail transmission and protocol conversion between electronic mail systems having different protocols.

Further, when an error occurs in each process, the error process can be performed in the process, so that the processing efficiency is not deteriorated unlike the conventional method of restarting the process from the transmission of the mail. .

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a first mail protocol conversion control system of the present invention.

FIG. 2 is a flow chart showing a process of a first mail transmission means 3 in the mail system A1 of the first mail protocol conversion control system of the present invention.

FIG. 3 is an outgoing mail waiting means 6 in the mail protocol converter 5 of the first mail protocol conversion control system of the present invention, a mail protocol converter 8,
Second mail sending means 9 and sending history updating means 10
6 is a flowchart showing the processing of FIG.

FIG. 4 is a block diagram showing an embodiment of a second mail protocol conversion control system of the present invention.

FIG. 5 is a flow chart showing the processing of the first mail transmission means 3 in the mail system A1 of the second mail protocol conversion control system of the present invention.

FIG. 6 shows the processing of the mail protocol conversion means 6, the second mail transmission means 8 and the transmission history update means 9 in the mail protocol conversion device 4 of the second mail protocol conversion control system of the present invention. It is a flow chart.

FIG. 7 is a block diagram showing an embodiment of a third mail protocol conversion control system of the present invention.

FIG. 8 is a flow chart showing the processing in the mail system A1 of the third mail protocol conversion control system of the present invention.

[Explanation of symbols]

 In FIGS. 1, 2 and 3, 1 mail system A 2 outgoing mail box 3 first mail sending means 4 receiving mail box for other mail systems 5 mail protocol converter 6 outgoing mail waiting means 7 mail status file Means 8 mail protocol conversion means 9 second mail sending means 10 sending history updating means 11 mail system B 12 receiving mailbox 1 in FIG. 4, FIG. 5 and FIG. 6 1 mail system A 2 sending mailbox 3 first Mail sending means 4 Mail protocol conversion device 5 Mail status file means 6 Mail protocol conversion means 7 Mail protocol conversion table 8 Second mail sending means 9 Outgoing history updating means 10 Mail system B 11 Receiving mailbox In FIGS. 7 and 8. , 1 mail Temu A 2-mail editor 3 mail status file means 4-mail protocol converter 5 mail protocol conversion table 6 mail transmission means 7 outgoing mailbox 8 mail system B 9 receiving mailbox

Claims (3)

(57) [Claims] 1. A mail protocol conversion control system for converting a mail protocol required for sending and receiving mail between electronic mail systems having different protocols, wherein a mail protocol conversion control system for another mail system having a different protocol is used. The first mail sending means that sets a mailbox and sends mail to the mailbox is set corresponding to each different protocol, takes out the mail from the own mail system, and converts the mail protocol by the preset conversion method However, it is a mail protocol conversion device for sending to other mail systems, and mail status file means for registering the status of holding mail and mail processing status, and mail from the other mail system mailbox in the own mail system. Take out the above An outgoing mail waiting means for registering in a mail status file means, a mail protocol converting means for taking out a mail from the mail status file means, converting a mail protocol by a preset conversion method, and returning the mail protocol to the mail status file means, Second mail sending means for sending the protocol-converted mail of the mail status file means to another mail system, and monitoring the status of the mail in the mail status file means and notifying the own mail system of the mail sending history And a mail history conversion means for realizing the mail protocol conversion control system. 2. A mail protocol conversion control system for converting a mail protocol required for transmitting and receiving a mail between electronic mail systems having different protocols, wherein: The first mail sending means for sending mail to the mail status file means and a mail protocol converter for receiving mail from the own mail system, converting the mail protocol, and sending the mail to another mail system from the own mail system. A mail status file means for receiving a mail and registering a status for holding the mail and the processing status of the mail, and taking out the mail from the mail status file means, referring to a mail protocol conversion table, converting the mail protocol, and setting the mail status F Mail protocol conversion means for returning to the mail means, second mail sending means for sending the protocol-converted mail of the mail status file means to another mail system, and monitoring the status of the mail in the mail status file means And a mail protocol conversion control system realized by including a transmission history update means for notifying the own mail system of a mail transmission history. 3. A mail protocol conversion control system for converting a mail protocol required for sending and receiving mail between electronic mail systems having different protocols, and registering a mail status holding a mail and a mail processing status. A mail status file means for editing, a mail editor means for editing a mail and placing the mail in the outgoing mailbox or the mail status file means, and a mail for which the mail status indicates protocol unconverted from the mail status file means To the mail protocol conversion table, converts the mail protocol and returns it to the mail status file means, and the mail status conversion means returns the mail status from the protocol. Mail protocol conversion control system implementing by providing removed mail showing the converted asynchronously, and mail transmission means for transmitting towards the other mail systems, a.